Guide Signs and Route Markers: Interstate, State, County and Destinations
Guide signs do not tell you what to do; they tell you where you are and where you are going. This domain tests route marker shapes and colors, numbering logic, and how to read destination and exit signs before the decision point.
Interstate and U.S. routes
The interstate shield is red, white and blue with INTERSTATE on the upper panel. Numbers follow direction: odd routes run north-south (I-25) and even routes run east-west (I-70). Three-digit interstates are loops or spurs off a parent route - I-225 loops around the east side of Denver off I-25, and I-270 spurs from I-70. U.S. highways use the white shield outline with black numerals and follow the same odd/even convention.
State, county and local markers
Colorado state highways use a black-and-white shield marker with the route number. County roads use the blue pentagon with yellow lettering, the marker most often misidentified in practice questions. Mile markers are small green signs with white numbers and they drive exit numbering: Colorado numbers exits by milepost counted from the southern or western state line, so exit 200 on I-70 lies 200 miles from the Utah line.
Destination, service and recreation signs
Green signs give destinations, distances and arrows; an advance guide sign appears a mile or more ahead and the exit direction sign sits at the gore. Blue signs mark services such as gas, food, lodging and hospitals. Brown signs mark recreation and cultural attractions. A TO placard beside a route marker means you are being directed toward that route, not that you are already on it.
Worked example
You see a green sign reading EXIT 205, 1 MILE, with a blue fuel symbol and a brown camera symbol. The green panel handles navigation - exit 205 is one mile ahead, numbered by milepost. The blue panel says fuel is available at that exit. The brown panel marks a recreation or point-of-interest attraction. You should be positioned for the exit by the advance sign, not at the gore.
Traps
Confusing the blue county pentagon with a state or interstate marker. Treating a TO marker as proof you are already on the route. Reading exit numbers as sequential instead of mile-based. Forgetting that guide signs stay green regardless of the type of road.